Female socket for electrical coupling



May 11, 1965 H. R. HAMEL FEMALE SOCKET FOR ELECTRICAL COUPLING 2 Sheets-Sheet 1 Filed March 5, 1962 yaw May 11, 1965 H. R. HAMEL 3,183,474

FEMALE SOCKET FOR ELECTRICAL COUPLING Filed March 5, 1962 2 Sheets-Sheet 2 mmvroza fiwa ooaserlmez United States Patent 3,183,474 FEMALE SGCKET FOR ELEQTRIQAL CQUFLING Harold Robert Hamel, Rolling Hills Estates, tl'alifi, assignor to Pacific Electricord Company, Gardena, Calii, a corporation of California Filed Mar. 5, 1962, Ser. No. 177,302 1 Claim. (G. 339-187) The present invention relates generally to electrical couplings of the plug and socket type such as used to interconnect electrical cables, and more particularly to the female socket members of such couplings and to the method of forming such sockets.

This invention finds one application in twist-lock type couplings in which the plug and socket are given relative rotative movement after assembly to lock the plug and socket together against involuntary removal. It provides for individual temporary mechanical support of the electrical components of the socket in the die cavity during the molding of the enclosing body of the socket, without permanent assembly or interconnection of the elements of such components. This invention further provides for the molding of undercuts in the body of the socket while enabling the core members, which provide passages in the body of the socket and establish such undercuts, to be readily removed from the molded socket body.

It is, therefore, one of the objects of the present invention to provide an improved female socket member for an electrical coupling in which the electrical components of the socket are supported and mounted in the molded body of the socket without other connection therebetween.

Another object of this invention is the provision of an improved female socket member for an electrical coupling having a molded body portion and providing undercut passageways into which elements of a cooperating male plug may be inserted upon relative rotary motion between the plug and socket after assembly.

A further object of this invention is an improved method of molding an insulating body about the electrical components of the female socket member of an electrical coupling which provides desirable economies in manufacture and simplicity of assembly and mounting of such components securely within the socket body.

Yet another object of this invention is an improved method of molding the body of a female socket member of an electrical coupling in which the electrical components of the socket are temporarily mounted on sectional core blades and supported solely thereby within a mold defining the exterior of the socket and which removes the sections of the core blades from the socket body by straight-line or successive rotary and straightline movements to provide undercut passages within the socket.

These and other objects and features of the invention will be readily apparent to those skilled in the art from the following specification and the appended drawings, in which:

FIGURE 1 is a perspective view of a multipart or seetional core used in the process of the present invention;

FIGURE 2 is a perspective view, with parts cut away, showing the electrical components of the socket supported upon core blades within a mold cavity;

FIGURE 3 is a longitudinal sectional view through the socket after the first, straight-line removal of the first sections of the core blades from the molded socket;

FIGURE 4 is a transverse sectional view on line 44 of FIGURE 3;

FIGURES is a longitudinal sectional view, similar to FIGURE 3, but with the second sections of the core blades removed from'the body of the socket to show the completed socket;

3,183,474 Patented May 11, 1965 FIGURE 6 is a transverse sectional view, similar to FIGURE 4, and also showing the second sections of the core blades removed from the socket;

FIGURE 7 is an elevational view of the front'face of the socket; and

FIGURE 8 is a perspective view of one form of male plug usable with the socket of this invention.

Referring to the appended drawings, the completed socket or female portion of the coupling is shown in FIGURES 5, 6 and 7, being designated generally at 11, and includes a generally cylindrical body portion 12 of molded insulating material having a flat front face 13 and a rear knob portion 14. The socket 11 may be mounted on the end of a cable 15, shown as a molded fiexible tubing enclosing three flexible conductors 17, 18 and 19. The insulating body 12 of the socket 11 is molded directly about the outer tubing'of cable 15 and the conductors 1'7, 18 and 19 when the socket is formed.

Three arcuate passageways 21, 22 and 23 are provided leading from the front face 13 of the body 12 into the interior thereof. Straddling each of the passageways 21, 22 and 23, and opening forwardly, are the opposed legs 24 and 25 of three conducting socket connectors or components 26, 27 and 28. The legs 24 are spaced from the legs 25 through the major portion of their length by their offset portions 29 which are rigidly secured to the legs 25 by means of rivets 31. The rear ends of the legs 25 are bent radially outwardly at 32 and are provided with holes therethrough through which extend the ends of the conductors 17, 18 and 19. The ends 32 of the legs 25 and of the conductors 17, 18 and 19 are then preferably electrically connected together as individual, electrically insulated terminals by means of soldering, brazing, welding or mechanical pressure, as at 33, to form good electrical connections.

The passageways 21, 22 and 23 are provided with rear, undercut, arcuate extensions 34, 35 and 36 to accommodate portions on the blades of male plugs when the plug and socket are given relative rotary movement after assembly. The passages 21, 22 and 23 are located at different radii with respect to the center of the socket 13, thereby to assist in the polarization of the coupling whereby the plug and socket members may be assembled with only a definite blade on the plug cooperating with an indexed definite jaw in the socket. A radially extending passage 37 communicates with the passageway. 21 adjacent one edge thereof to receive a prong locking element where provided on the corresponding blade of the male plug. The leg 24 of the socket jaw 26 is provided with a transverse groove 38 formed therein which commun cates with the passage 37 and which receives such locking prong on the blade of the male plug when the plug and socket are given relative rotary movement after assembly.

The sectional core and jaw support 40 used in the molding process of this invention is shown in FIGURE 1, and supporting the socket jaws in place in a die in FIGURE 2. The core 40 comprises a head 41 having a front face 42 against which the front face 13 of the socket 11 is molded. Supported in and extending from the front face 42 of the head 41 are sectional core blades 43, 44 and 45. The core blade 43 is made up of a pair of sections 46 and 47 meeting in a scarf joint at 48. Each of the core blades 44 and 45 includes sectional portions 51 and 52 with scarf joints at 53. The core blade sections 46 and 51 extend axially only from the core head 41 and are preferably retained therein by means of setscrews 54. The core blade sections 47 and 52 are provided with circumferentially offset portions 55 and are preferably freely axiallyslidab'ly separable from the core head 41. The section 46 is provided with a radially extending enlargement 56 which forms the passage 37 in the body 12 of the socket, and the section 47 is provided with a small radial exten- 4:; C3 sion at 57 which is received within the groove'38 in the leg 25 of the jaw 26.

The die sections and the conducting components of the socket member are shown together in FIGURE 2 prior to the injection of the plastic molding material for the body of the socket. The core 40 has its head 41 received within a complementary recess in a first die member 61, with which cooperates a pair of separable die members 62 and 63 which together provide a die cavity 64 whose efining surfaces mold the exterior of the body 12 of the socket 11. The conducting jaws 26, 27 and 28 ar mounted upon the core blades 43, 44 and 45, respectively, with the legs 24 and 25 of the jaws embracing the core blades and opening forwardly toward the core face 42. The jaw 26 is located with its axially extending edge against the core part 56, and the core part 57 on the core section 47 is received within the groove 38 in the leg 24 of the jaw 26. With the die and core parts assembled, the conducting parts of the socket will be supported in the die cavity solely by the core blades, as shown in FIGURE 2. Thereafter the die cavity is filled with a selected insulating material to form the body 12 of the socket 11. This material may be any of the molding rubbers or plastics; for example, a thermoplastic vinyl material, such as polyvinyl chloride, or phenol formaldehyde or polystyrene, and the die cavity may be filled by any known molding process, such as by transfer molding or injection of the molding material.

After the molding operation the die sections 452 and 63 are preferably first separated to release the molded socket body. Thereafter the core and core blade sections are preferably separated from the molded socket body and the conducting parts therein in the following manner: separation of the core head 41 from the socket body 12 in an axial direction results in the core blade sections 46 and 51 being withdrawn from the socket body with the head 41 in a straight-line movement to uncover the counterclockwise portions of the passageways 21, 22 and 23, leaving the socket and core sections 47 and 52 as shown in FIGURES 3 and 4; thereafter, preferably after cooling, the core blade sections 47 and 52 are rotated, either individually or together, in a counterclockwise direction, as shown by the arrows in FIGURE 4, to remove the offset portions 55 thereof from the undercut passages 34, 35 and 36, whereupon the otfset portions 55 are aligned with the passageways 21, 22 and 23. The core sections 47 and 52 may now be withdrawn from the body 12 of the socket 11 by a straight-line, axial movement. This completes the socket in the form shown in FIGURES 5 through 7.

The resulting socket or female coupling portion may be used'with male coupling portions or plugs having varied blade configurations. For example, the plug bladesmay be straight, with no rotary interlocking thereof with the socket. Alternatively, the plug blades may include laterally offset portions, such as shown at 71 on the blades 72 of the plug 70 of FIGURE 8, received within the undercut passages 34, 35 and 36, or any of them, upon relative rotary movement between the plug and socket after assembly, to thereby interlock the plug and socket against involuntary separation. In both of these forms of plug blades polarization is secured from the non-uniform locations of the passageways 21, 22 and 23. Again, a plug blade or blades may be provided with a prong (74 in FIGURE 8) receivable in the socket-passage 37 as the plug and socket are assembled and rotated into the groove 38 upon relative rotary movement between the plug and presents desirable features of economy, simplicity and ease of manufacture which stem both from its structure and from the method of forming the same by means of sectional core blades which form the sole support for the conducting components of the jaw during the molding operation and which provide for the molding of undercut portions within the socket while retaining easy removal of the core blade sections therefrom; and while a certain preferred embodiment of the invention has been particularly illustrated and described, and the methodof forming the socket has been described in connection therewith, it will be understood that the invention is not limited thereto, as many variations in the socket and the method of forming the same will be apparent to those skilled in the art, and the invention is to be given its broadest interpretation within the terms of the following claim.

I claim:

A female socket member for receiving a male plug, said socket member and male plug forming an electrical coupling, comprising:

a unitary main body portion of molded insulating material and having a fiat front face;

three arcuate passageways formed in said main body leading from the front face rearwardly into the interior thereof, one of said passageways being formed with a radially extending groove along its length, the rear portion of said one passageway having a circumferential continuation of said radially extending groove, the other two of said arcuate passageways being identical and formed on a different radius with respect to the center of said main body than the radius of said one of said passageways, and the rear of each of said passageways being formed with undercut, arcuate extensions in the same direction as the direction of said circumferential continuation of said one passageway;

a pair of arcuate electrical conducting socket connections straddling each of said passageways along the major portion of the length of said passageways, the front end of each of said connectors being flared forwardly and radially and the rear of each of said pairs of said connectors being electrically interconnected, the radially outermost of the pair of socket connectors in said one of said passageways having a radially outwardly directed groove conforming to said radially extending groove of said one of said passageways to receive a complementary indexing prong on said male plug;

a cable having three conduits extending from the rear of said main body, said conduits being electrically connected to the rear of said conducting socket elements;

and said conducting socket elements and the front portion of said cable conduits being solely and independgngy supported by the molded material of said main References Cited by the'Examiner UNITED STATES PATENTS JOSEPH D. SEERS, Primary Examiner. 

